The present invention relates to a closure for a medicament well.
More preclcely, the invention relates to a closure for a medicament well on a cannula, wlth a central, closing body and, If deslred, a round body and a sklrt extending substantially in parallel with the latter.
There is mainly one kind of intravenous cannulae on the market at present, vlz. a kind where a clrcular medicament well projecting normally to the liquid channel in the lntravenous cannula is closed from above by the ald of a conventional cap, whlch is commonly fastened to the sleeve of the medicament well by the ald of a more or less sturdy fastening strap.
The present cannulae with a medicament well of a conventional kind show the inherent deficiency that after administration of medicament and removal of the administrating syringe, there is always a small volume of medicament solutlon left in the well due to the counterpressure from the liquid flowing in the cannula.
This phenomenon may represent quite a health hazard, since the volume of medicament remaining in the medicament well may act as a substrate for bacteria, or the medicament may be subjected to decomposition or metamorphosis due to influence from the outside environment.
This is probably one of the reasons for the fact that this kind of intravenous cannula ls not accepted by the FDA on the American market.
Body heat may also cause undesirable changes.
Often, hours may pass between each time the medicament well is used, and this enhances the hazard of undesirable changes.
When the medicament well is used again, the medicament phase which may be modified or decomposed will be pushed into the cannula and introduced into the body, which may cause undesirable and even dangerous states.
Another aspect that should be considered in this connection is that when small volumes of medicaments are administered it may occur that not all of the medicsmerit is injected, since some of it is left in the well.